code 173 and idles ruff

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Jun 7, 2009 | 03:39 PM

02Ford4x4

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code 173 and idles ruff

I have a 93 f150. It idles a little ruff and sometimes tries to die after coming to a stop. I can't tell anything is wrong with it going down the road though. The only code is 173 system rich. Fuel pressure regulator seems ok, 38 psi idling and unplugged FPR goes to about 50psi. Is there something else to check or just replace the oxygen sensors? Also has new coil, distributor cap and rotor.

Jun 7, 2009 | 05:59 PM

subford

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From: Easton,Ks

I take it you are talking about a 4.9L, if not the pressure is to high.

Jun 7, 2009 | 06:17 PM

02Ford4x4

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5.0 What is the pressure supposed to be? I thought I read that it was supposed to be around 38psi. If it is too high, does that mean the fpr needs replaced?

Jun 7, 2009 | 06:26 PM

subford

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From: Easton,Ks

The pressure should be about 32-34 PSI at Idle and 42 PSI max with the vacuum hose off the FPR.
Yes either the FPR or you have a pinched line going back to the fuel tanks.

Jun 7, 2009 | 07:07 PM

02Ford4x4

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I just went and rechecked it twice and the pressure was 34psi at idle and 43psi with vacuum unplugged. Don't know what happened first time I checked it. The engine just barely idles ruff and giving it gas up to about 1500rpms. Just enough to feel it. The coil went out a few days ago. I am thinking now that the plugs may need to be changed. Could the plugs cause the code 173?

Jun 7, 2009 | 07:32 PM

subford

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From: Easton,Ks

Yes plugs or wires if it is miss firing.
Was there any fuel in the vacuum hose or coming out of the nipple when you took the hose off the FPR.

Jun 7, 2009 | 07:35 PM

subford

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From: Easton,Ks

173:
Possible Causes:

--Fuel injectors.
--HO2S.
--Secondary Air Injection (AIR) system.
--PCV/Hose.
--Vacuum.
--CANP.
--MAP sensor.
--Electronic Ignition Coil Failure.

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Jun 8, 2009 | 08:22 PM

02Ford4x4

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I replaced the plugs and checked the wires and seems to run a little better but it didn't change the idle any. The idle will jump around sometimes from 500 rpm to 900. It went dead twice when it did this. I unplugged the map sensor and the idle went up some but it wasn't steady, it went up and down. Could the map sensor be causing all of this?

Before I new anything about the map sensor, I think(can't remember) I unplugged it and the engine died, which I read means that the map is bad. I can't get it to do it now though.